Process of tanning fish-skins or the like.



UNITED STATES PATENT caries.

KBISTIAN IBENDIXEN, OF COPENHAGEN, DENMARK.

PROCESS OF TANNING- FISH-SKINS OR THE LIKE.

No Drawing. Application filed December To all whom it may concern:

Be it known that KBIs'rmN BENDIXEN, manufacturer, merchant, a subject of. the Kingdom of Denmark, residing at No. 10 Puggaardsgade, Copenhagen, Denmark, has invented certain new and useful Improvements in Processes for Tanning Fish-Skins or the like; and he does hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it apper tains to make and use the same.

The invention relates to a'process for tanning fish skins, such as the skins of sharks, and the like, and the skins of whales, whereby leather may be produced having the same qualities as the leather ordinarily used. in the various industries.

Heretofore it has been attempted to employ the ordinary methods of tanning deer skins in tanning fish skins. These methods with certain modifications, including treatment with arsenic and'lime, and a subse quent manure-bath, have been used with difficulty and unsatisfactory results in treating fish skins. In attempting this, the fact has been overlooked that treatment withlime, though necessa intanning deer skins in order to remove t 0 hair 1s unnecessary in tanning fish skins or the e which have no hair.

The method by which fish sln'ns, from whic the salt remaining after the saltmg is washed out and the quills or the like have been removed, are treated in such a manner that theskins are freed from their great content of oil and other fatty matter so that they come quite similar in qualit to deer when the latter have been d from hair by the treatment with lime and are ready for the tanning step proper. I

This result is obtained by a simple treatment with fat-removing means, and then washing the skins and neutrahzmg the remaining fat-removing means. As fat-removing means, a lye such as a solut1on of sodium lye, the of which depends upon the particular kind of fish skin to be Specification 01. Letters Patent.

present invention has for its ob'eot. a

Patented Au 7, 1917.

2 9, 1914. Serial No. 879,461.

treated, may be used. The excess of lye is neutrallzed after all or the requiredamount of o1l or fatty matter has been removed, by applymg a weak acid solution, such as for instance a solution of muriatic acid... The washing, wh1ch can be performed either before or after the lye and acid treatments, is done with cold or warm water.

After this simple treatment, the fish skins are ready to undergo the tanning step proper, m which any ordinary method is followed, and they are like ordinary skins capable of being made to leather or washleather, as desired. I

If whale skin is to be transformed into wash-leather, it is preferable that all of its content of oil shall not be removed, but only a suitable part of the same. Otherwise, durmg the tanmng step, oil would again have to be supplied to the skin.

' By employing the method described, the fish skms are not only rapidly and cheaply prepared for the tanning step, but besides,

. a eat uantity of dgras is obtained as a y-pro uct from the oil and fatty matter of thesln'ns, which substance is ordinarily produced only as a by-product from the wash-leather manufacturer.

Having thus describedthe invention, what is desired tobe claimed and to be secured by Letters-Patent, is:

1.v The herein described process, whlch consists in first treating fish-skins or the like with an alkaline solution for a suflicient length of time to remove part of the oil and.

fatty matter and leave the amount necessary .for wash leather, then neutralizing the remaining alkali with acid solution, and washing the skins with water.

2. The herein described process which consists in firsttreating fish skins or the like with an alkaline solutlon to remove a art only of the oil and fatty matter and t en neutralizing the rema' alkal 1 with a weakened solution, and was g wlth water. In testimon whereof, I aflix my signature in presence 0 two witnesses.

I KRISTIAN BENDIXEN. 

